This looks like a what I'd called a 'cobblers' watch, meaning its been created from various components that didn't originally come together or was released as an official Bulova watch.

The dial and movement are a give away, as is the lack of Bulova identification on the case.

The 10AN was Bulova's primary movement through the 1920s and into the early 30s and seems a bit early for this watch, but was also a common movement for cobbler watches due to their high numbers and ease of repurpose.

I'd like to see the case back in mote detail if I could, but at the moment I'm thinking 'Non-conforming' which basically means it's a watch made of various Bulova and non-Bulova parts.